I'm afraid to announce that we've recently discovered a major error in one of the files used by the climate model. The file in question specifies levels of man-made sulphate emissions but due to a problem with the file specification, models have been inputting greatly reduced levels throughout their runtime. The consequence of this is that aerosols responsible for "global dimming" (cooling) are not present in sufficient amounts and models have tended to warm up too quickly. The file specification error is also responsible for causing models to crash in 2013 which is how we originally came across the problem.
Unfortunately, all the data returned to us so far has been affected by this problem. While the data is scientifically very useful, and will certainly form the basis of future research (it allows us to investigate the full effect of greenhouse gas emissions without global dimming), it doesn't enable us to compare the models' performance against real world observations of the 20th century since such an important component is missing. In order to do the experiment we intended, we unfortunately have no choice but to start models again from the beginning.
So what now? We've spent the last few days fixing the error and we're in the process of generating and testing new model versions which should be ready in the next week or so.
We very much hope you'll be prepared to keep running with us and, if so, all you need do is keep running your existing experiment and you will be automatically upgraded to a new model version next time you connect to our server via the automated system. We've removed all the old model versions so if you're waiting for a new workunit, they should be available within the week.
Apologies to all our participants on behalf of the CPDN team, it's a big disappointment to have to give you this news.
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Nick Faull
Project Coordinator
Climateprediction.net
University of Oxford
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